// 读取税前工资 s（浮点数），按区间用 switch 计算税率，输出税后工资（两位小数）
#include <stdio.h>

int main(void)
{
    double s;
    if (scanf("%lf", &s) != 1) {
        return 0;
    }

    // 将浮点区间映射到整数分类，再用 switch 选择税率
    int grade;
    if (s < 1000.0) grade = 0;
    else if (s < 2000.0) grade = 1;
    else if (s < 3000.0) grade = 2;
    else if (s < 4000.0) grade = 3;
    else grade = 4;

    double rate;
    switch (grade) {
        case 0: rate = 0.0;  break;
        case 1: rate = 0.10; break;
        case 2: rate = 0.15; break;
        case 3: rate = 0.20; break;
        case 4: rate = 0.25; break;
        default: rate = 0.0; break; // 理论不会触发
    }

    double net = s * (1.0 - rate);
    printf("%.2f", net);
    return 0;
}